net: Convert GRO SKB handling to list_head.
[linux-2.6-block.git] / net / ipv6 / ip6_offload.c
CommitLineData
d1da932e
VY
1/*
2 * IPV6 GSO/GRO offload support
3 * Linux INET6 implementation
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
9 */
10
11#include <linux/kernel.h>
12#include <linux/socket.h>
13#include <linux/netdevice.h>
14#include <linux/skbuff.h>
c6b641a4 15#include <linux/printk.h>
d1da932e
VY
16
17#include <net/protocol.h>
18#include <net/ipv6.h>
b8921ca8 19#include <net/inet_common.h>
d1da932e
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20
21#include "ip6_offload.h"
22
23static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
24{
25 const struct net_offload *ops = NULL;
26
27 for (;;) {
28 struct ipv6_opt_hdr *opth;
29 int len;
30
31 if (proto != NEXTHDR_HOP) {
32 ops = rcu_dereference(inet6_offloads[proto]);
33
34 if (unlikely(!ops))
35 break;
36
37 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
38 break;
39 }
40
41 if (unlikely(!pskb_may_pull(skb, 8)))
42 break;
43
44 opth = (void *)skb->data;
45 len = ipv6_optlen(opth);
46
47 if (unlikely(!pskb_may_pull(skb, len)))
48 break;
49
fc6fb41c 50 opth = (void *)skb->data;
d1da932e
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51 proto = opth->nexthdr;
52 __skb_pull(skb, len);
53 }
54
55 return proto;
56}
57
d1da932e
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58static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
59 netdev_features_t features)
60{
61 struct sk_buff *segs = ERR_PTR(-EINVAL);
62 struct ipv6hdr *ipv6h;
63 const struct net_offload *ops;
64 int proto;
65 struct frag_hdr *fptr;
802ab55a 66 unsigned int payload_len;
d1da932e
VY
67 u8 *prevhdr;
68 int offset = 0;
91a48a2e 69 bool encap, udpfrag;
d3e5e006 70 int nhoff;
07b26c94 71 bool gso_partial;
d1da932e 72
d3e5e006
ED
73 skb_reset_network_header(skb);
74 nhoff = skb_network_header(skb) - skb_mac_header(skb);
d1da932e
VY
75 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
76 goto out;
77
91a48a2e
HFS
78 encap = SKB_GSO_CB(skb)->encap_level > 0;
79 if (encap)
1e16aa3d 80 features &= skb->dev->hw_enc_features;
d3e5e006
ED
81 SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
82
d1da932e
VY
83 ipv6h = ipv6_hdr(skb);
84 __skb_pull(skb, sizeof(*ipv6h));
85 segs = ERR_PTR(-EPROTONOSUPPORT);
86
87 proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
b917eb15 88
91a48a2e 89 if (skb->encapsulation &&
7e13318d 90 skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
ee80d1eb
WB
91 udpfrag = proto == IPPROTO_UDP && encap &&
92 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
91a48a2e 93 else
ee80d1eb
WB
94 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
95 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
91a48a2e 96
d1da932e 97 ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1 98 if (likely(ops && ops->callbacks.gso_segment)) {
d1da932e 99 skb_reset_transport_header(skb);
f191a1d1 100 segs = ops->callbacks.gso_segment(skb, features);
d1da932e 101 }
d1da932e 102
6b6ebb6b 103 if (IS_ERR_OR_NULL(segs))
d1da932e
VY
104 goto out;
105
07b26c94
SK
106 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
107
d1da932e 108 for (skb = segs; skb; skb = skb->next) {
d3e5e006 109 ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
3d0241d5 110 if (gso_partial && skb_is_gso(skb))
802ab55a
AD
111 payload_len = skb_shinfo(skb)->gso_size +
112 SKB_GSO_CB(skb)->data_offset +
113 skb->head - (unsigned char *)(ipv6h + 1);
114 else
115 payload_len = skb->len - nhoff - sizeof(*ipv6h);
116 ipv6h->payload_len = htons(payload_len);
d3e5e006
ED
117 skb->network_header = (u8 *)ipv6h - skb->head;
118
91a48a2e 119 if (udpfrag) {
7dd7eb95 120 int err = ip6_find_1stfragopt(skb, &prevhdr);
e3e86b51
DM
121 if (err < 0) {
122 kfree_skb_list(segs);
7dd7eb95 123 return ERR_PTR(err);
e3e86b51 124 }
7dd7eb95 125 fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
d1da932e 126 fptr->frag_off = htons(offset);
53b24b8f 127 if (skb->next)
d1da932e
VY
128 fptr->frag_off |= htons(IP6_MF);
129 offset += (ntohs(ipv6h->payload_len) -
130 sizeof(struct frag_hdr));
131 }
91a48a2e
HFS
132 if (encap)
133 skb_reset_inner_headers(skb);
d1da932e
VY
134 }
135
136out:
137 return segs;
138}
139
299603e8
JC
140/* Return the total length of all the extension hdrs, following the same
141 * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
142 */
143static int ipv6_exthdrs_len(struct ipv6hdr *iph,
144 const struct net_offload **opps)
145{
810c23a3
JC
146 struct ipv6_opt_hdr *opth = (void *)iph;
147 int len = 0, proto, optlen = sizeof(*iph);
299603e8
JC
148
149 proto = iph->nexthdr;
150 for (;;) {
151 if (proto != NEXTHDR_HOP) {
152 *opps = rcu_dereference(inet6_offloads[proto]);
153 if (unlikely(!(*opps)))
154 break;
155 if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
156 break;
157 }
810c23a3
JC
158 opth = (void *)opth + optlen;
159 optlen = ipv6_optlen(opth);
299603e8
JC
160 len += optlen;
161 proto = opth->nexthdr;
162 }
163 return len;
164}
165
d4546c25
DM
166static struct sk_buff *ipv6_gro_receive(struct list_head *head,
167 struct sk_buff *skb)
d1da932e
VY
168{
169 const struct net_offload *ops;
d4546c25 170 struct sk_buff *pp = NULL;
d1da932e
VY
171 struct sk_buff *p;
172 struct ipv6hdr *iph;
173 unsigned int nlen;
174 unsigned int hlen;
175 unsigned int off;
bf5a755f 176 u16 flush = 1;
d1da932e 177 int proto;
d1da932e
VY
178
179 off = skb_gro_offset(skb);
180 hlen = off + sizeof(*iph);
181 iph = skb_gro_header_fast(skb, off);
182 if (skb_gro_header_hard(skb, hlen)) {
183 iph = skb_gro_header_slow(skb, hlen, off);
184 if (unlikely(!iph))
185 goto out;
186 }
187
299603e8 188 skb_set_network_header(skb, off);
d1da932e
VY
189 skb_gro_pull(skb, sizeof(*iph));
190 skb_set_transport_header(skb, skb_gro_offset(skb));
191
192 flush += ntohs(iph->payload_len) != skb_gro_len(skb);
193
194 rcu_read_lock();
195 proto = iph->nexthdr;
196 ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1 197 if (!ops || !ops->callbacks.gro_receive) {
d1da932e 198 __pskb_pull(skb, skb_gro_offset(skb));
57ea52a8 199 skb_gro_frag0_invalidate(skb);
d1da932e
VY
200 proto = ipv6_gso_pull_exthdrs(skb, proto);
201 skb_gro_pull(skb, -skb_transport_offset(skb));
202 skb_reset_transport_header(skb);
203 __skb_push(skb, skb_gro_offset(skb));
204
205 ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1 206 if (!ops || !ops->callbacks.gro_receive)
d1da932e
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207 goto out_unlock;
208
209 iph = ipv6_hdr(skb);
210 }
211
212 NAPI_GRO_CB(skb)->proto = proto;
213
214 flush--;
215 nlen = skb_network_header_len(skb);
216
d4546c25 217 list_for_each_entry(p, head, list) {
d1da932e
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218 const struct ipv6hdr *iph2;
219 __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
220
221 if (!NAPI_GRO_CB(p)->same_flow)
222 continue;
223
299603e8 224 iph2 = (struct ipv6hdr *)(p->data + off);
67ba4152 225 first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
d1da932e 226
299603e8
JC
227 /* All fields must match except length and Traffic Class.
228 * XXX skbs on the gro_list have all been parsed and pulled
229 * already so we don't need to compare nlen
230 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
231 * memcmp() alone below is suffcient, right?
232 */
233 if ((first_word & htonl(0xF00FFFFF)) ||
d1da932e
VY
234 memcmp(&iph->nexthdr, &iph2->nexthdr,
235 nlen - offsetof(struct ipv6hdr, nexthdr))) {
236 NAPI_GRO_CB(p)->same_flow = 0;
237 continue;
238 }
239 /* flush if Traffic Class fields are different */
240 NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
241 NAPI_GRO_CB(p)->flush |= flush;
03d56daa 242
1530545e
AD
243 /* If the previous IP ID value was based on an atomic
244 * datagram we can overwrite the value and ignore it.
245 */
246 if (NAPI_GRO_CB(skb)->is_atomic)
247 NAPI_GRO_CB(p)->flush_id = 0;
d1da932e
VY
248 }
249
1530545e 250 NAPI_GRO_CB(skb)->is_atomic = true;
d1da932e
VY
251 NAPI_GRO_CB(skb)->flush |= flush;
252
4de462ab 253 skb_gro_postpull_rcsum(skb, iph, nlen);
d1da932e 254
fcd91dd4 255 pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
d1da932e 256
d1da932e
VY
257out_unlock:
258 rcu_read_unlock();
259
260out:
5f114163 261 skb_gro_flush_final(skb, pp, flush);
d1da932e
VY
262
263 return pp;
264}
265
d4546c25
DM
266static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
267 struct sk_buff *skb)
fac8e0f5 268{
815d22e5
TH
269 /* Common GRO receive for SIT and IP6IP6 */
270
fac8e0f5
JG
271 if (NAPI_GRO_CB(skb)->encap_mark) {
272 NAPI_GRO_CB(skb)->flush = 1;
273 return NULL;
274 }
275
276 NAPI_GRO_CB(skb)->encap_mark = 1;
277
278 return ipv6_gro_receive(head, skb);
279}
280
d4546c25
DM
281static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
282 struct sk_buff *skb)
b8921ca8
TH
283{
284 /* Common GRO receive for SIT and IP6IP6 */
285
286 if (NAPI_GRO_CB(skb)->encap_mark) {
287 NAPI_GRO_CB(skb)->flush = 1;
288 return NULL;
289 }
290
291 NAPI_GRO_CB(skb)->encap_mark = 1;
292
293 return inet_gro_receive(head, skb);
294}
295
299603e8 296static int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
d1da932e
VY
297{
298 const struct net_offload *ops;
299603e8 299 struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + nhoff);
d1da932e
VY
300 int err = -ENOSYS;
301
294acf1c
PA
302 if (skb->encapsulation) {
303 skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
feec0cb3 304 skb_set_inner_network_header(skb, nhoff);
294acf1c 305 }
feec0cb3 306
299603e8 307 iph->payload_len = htons(skb->len - nhoff - sizeof(*iph));
d1da932e
VY
308
309 rcu_read_lock();
299603e8
JC
310
311 nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
f191a1d1 312 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
d1da932e
VY
313 goto out_unlock;
314
299603e8 315 err = ops->callbacks.gro_complete(skb, nhoff);
d1da932e
VY
316
317out_unlock:
318 rcu_read_unlock();
319
320 return err;
321}
322
feec0cb3
ED
323static int sit_gro_complete(struct sk_buff *skb, int nhoff)
324{
325 skb->encapsulation = 1;
7e13318d 326 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
feec0cb3
ED
327 return ipv6_gro_complete(skb, nhoff);
328}
329
815d22e5
TH
330static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
331{
332 skb->encapsulation = 1;
333 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
334 return ipv6_gro_complete(skb, nhoff);
335}
336
b8921ca8
TH
337static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
338{
339 skb->encapsulation = 1;
340 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
341 return inet_gro_complete(skb, nhoff);
342}
343
d1da932e
VY
344static struct packet_offload ipv6_packet_offload __read_mostly = {
345 .type = cpu_to_be16(ETH_P_IPV6),
f191a1d1 346 .callbacks = {
f191a1d1
VY
347 .gso_segment = ipv6_gso_segment,
348 .gro_receive = ipv6_gro_receive,
349 .gro_complete = ipv6_gro_complete,
350 },
d1da932e
VY
351};
352
61c1db7f
ED
353static const struct net_offload sit_offload = {
354 .callbacks = {
61c1db7f 355 .gso_segment = ipv6_gso_segment,
815d22e5 356 .gro_receive = sit_ip6ip6_gro_receive,
feec0cb3 357 .gro_complete = sit_gro_complete,
61c1db7f
ED
358 },
359};
360
b8921ca8
TH
361static const struct net_offload ip4ip6_offload = {
362 .callbacks = {
363 .gso_segment = inet_gso_segment,
364 .gro_receive = ip4ip6_gro_receive,
365 .gro_complete = ip4ip6_gro_complete,
366 },
367};
368
815d22e5
TH
369static const struct net_offload ip6ip6_offload = {
370 .callbacks = {
371 .gso_segment = ipv6_gso_segment,
372 .gro_receive = sit_ip6ip6_gro_receive,
373 .gro_complete = ip6ip6_gro_complete,
374 },
375};
c6b641a4 376static int __init ipv6_offload_init(void)
d1da932e 377{
c6b641a4
VY
378
379 if (tcpv6_offload_init() < 0)
380 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
c6b641a4
VY
381 if (ipv6_exthdrs_offload_init() < 0)
382 pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
383
d1da932e 384 dev_add_offload(&ipv6_packet_offload);
61c1db7f
ED
385
386 inet_add_offload(&sit_offload, IPPROTO_IPV6);
815d22e5 387 inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
b8921ca8 388 inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
61c1db7f 389
c6b641a4 390 return 0;
d1da932e
VY
391}
392
c6b641a4 393fs_initcall(ipv6_offload_init);